THE  QUANTITATIVE  DETERMINATION  OF  ALKALOIDS 
BY  MEANS  OF  IMMISCIBLE  SOLVENTS 

BY 

MIRIAM  GERTRUDE  BUCK 
B.  A.  University  of  Illinois 
1920 


THESIS 

Submitted  in  Partial  Fulfillment 
of  the  Requirements  for  the 
Degree  of 

MASTER  OF  SCIENCE 
IN  CHEMISTRY 
IN 

THE  GRADUATE  SCHOOL 

OF  THE 

UNIVERSITY  OF  ILLINOIS 


1921 


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UNIVERSITY  OF  ILLINOIS 


THE  GRADUATE  SCHOOL 


September  26  1Q9  1 


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I HEREBY  RECOMMEND  THAT  THE  THESIS  PREPARED  UNDER  MY 


SUPERVISION  BY-  GERTRUDE  BUCK 


ENTITLED THE  QUANTITATIVE  DETERMINAT 1 ON  ON  ALKALOIDS 


BY  MEANS  0?  IMmISCIELE  SOLVENTS 


BE  ACCEPTED  AS  FULFILLING  THIS  PART  OF  THE  REQUIREMENTS  FOR 
THE  DEGREE  OF  ...mASTER  . 0E_  SCIENCE 


Recommendation  concurred  in* 


Committee 

on 

Final  Examination* 


*Required  for  doctor’s  degree  but  not  for  master’s 


. 


■ 


■ 


I wish  to  express  ray  sincere  thanks  to 
Professor  G-.D.Beal 

for  the  suggestion  of  this  problem  and 
the  interest  he  has  shown  during  the 
experimental  work. 


Digitized  by  the  Internet  Archive 
in  2015 


https://archive.org/details/quantitativedeteOObuck 


TABLE  OP  CONTENTS. 


I.  INTRODUCTION:  DISCUSSION  OP  THE  PROBLEM  p.  1 

I I.  HISTORICAL. 

I I I.  EXPERIMENTAL. 

1.  Preparation  of  the  tartrates  of  nicotine. 

2.  Preparation  of  nicotine  hydrochloride. 

3.  Preparation  of  pure  nicotine. 

4.  Determination  of  the  equilibrium  conditions  for  the 
partition  of  nicotine  between  aqueous  neutral  and  acid 
solutions  and  an  immiscible  solvent ( ether ) : 

(at)  Extraction  of  the  neutral  or  acid  aqueous  solu- 
tion with  ether. 

(b)  Conditions  of  equilibrium  in  systems  in  which 
the  alkaloid  is  being  removed  from  its  ether 
solution  by  an  acid. 

(d)  Extraction,  with  ether,  of  nicotine  salt  solu- 
tions to  which  sodium  hydroxide  has  been  added 
in  amount  equivalent  to  the  acid  in  the  salt. 


IV. SUMMARY. 


12 


BIBLIOGRAPHY. 


13 


OJ  vo 


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THE  QUANTITATIVE  DETERMINATION  OF  ALKALOIDS 
BY  MEANS  OF  IMMISCIBLE  SOLVENTS. 


I.  INTRODUCTION:  DISCUSSION  OF  THE  PROBLEM. 


One  of  the  oldest  and  most  widely  used  methods  of  alkaloL  - 
al  assay  is  based  upon  the  principle  that  the  majority  of  alka- 
loids are  insoluble  or  only  slightly  soluble  in  water  while  their 
salts  are  insoluble  in  the  organic  solvents  which  are  immiscible 
with  water.  This  method  is  known  as  the  "shaking  out"  process, 
made  familiar  by  the  " Dragendorff " ( 1 ) method  of  plant  analy- 
sis and  the  "Stas-Otto" ( 2)  method  for  no i son  assay.  The  accur- 
acy of  the  method  depends  on  several  assumptions : first , that 
the  alkaloidal  salt  is  insoluble  in  organic  solvents;  second, 
that  the  free  alkaloid  is  insoluble  in  neutral  aqueous  solutions; 
third,  that  there  is  no  hydrolysis  of  the  alkaloidal  salt  by  the 
water  present;  and  fourth,  that  there  is  no  decomposition  of  the 
alkaloid  by  the  organic  solvent.  Dra.gendorff  and  Otto  must  have 
recognized  that  the  principle  was  not  absolute  as  they  make  men- 
tion of  individual  exceptions. 

In  most  alkaloidal  assays  of  this  type,  the  sample  is  first 
extracted  with  dilute  acid.  This  dilute  acid  solution  is  then 
shaken  with  an  organic  solvent  to  remove  such  substances  as, col- 
oring matter,  essential  oils,  certain  organic  acids,  bitter  prin- 
ciples, tannins,  etc.,  which  would  later  interfere  with  the  quan- 
titative determination  of  the  alkaloid.  The  solution  is  then 
made  alkaline  and  shaken  with  an  immiscible  solvent.  Purifica- 
tion is  carried  out  by  shaking  the  organic  solvent  layer  with  can 
acid,  making  alkaline,  and  again  shaking  with  the  immiscible  sol- 
vent. This  is  repeated  several  times.  The  organic  solvent  is  then 
removed  by  evaporation  and  the  residue  determined  by  direct  weight, 
by  dissolving  in  standard  acid  and  titrating  the  excess  acid  with 
standard  alkali,  or  by  the  uie  of  special  precipitation  reagents 
for  individual  alkaloids. 

Beal  and  Lewis  (3)  eall  attention  to  several  sources  of  er- 
ror which  are  introduced  during  the  process.  In  the  first  place, 
the  alkaloidal  salt  may  be  slightly  soluble  in  the  organic  sol- 
vent. Then,  too,  there  is  the  possibility  of  the  alkaloidal  salt 
being  hydrolyzed,  by  the  water  present,  into  free  alkaloid  and 
acid,  and  this  free  alkaloid  would  be  readily  soluble  in  the  or- 
ganic solvent.  There  are  a few  cases  where  the  organic  solvent 
decomposes  the  alkaloid  or  combines  with  it.  These  factors  cause 
a decrease  in  the  amount  of  alkaloid  in  the  acid  solution  and  a 
corresponding  decrease  in  total  alkaloid  at  the  end  of  the  assay. 
Finally,  the  shaking  out  of  the  alkaloidal  solution  in  organic 
solvent  introduces  the  possibility  of  the  insolubility  or  slow 
solubility  of  the  salt  formed  in  the  acid  solution. 


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2. 


It  is  the  nurpose  of  this  work  to  obtain  results  showing 
the  partition  Of  the  alkaloid,  nicotine  in  particular,  between 
the  acid  layer  and  the  immiscible  solvent  using  hydrochloric 
and  tartaric  acids  under  different  concentration  conditions. 
Equilibrium  conditions  were  determined  by  shaking  the  acid  solu- 
tion of  the  alkaloid  with  the  organic  solvent  and  also  by  shak- 
ing the  solution  of  the  alkaloid  in  the  organic  solvent  with  an 
acid . 


Results  are  expressed  in  terms  of  the  " extraction  factor", 
a term  introduced  by  Beal  and  Lewis  (4),  in  their  work  of  the 
same  nature.  By  "extraction  factor"  is  meant  the  ratio  of  the 
amount  of  alkaloid  in  the  layer  of  added  solvent  to  the  amount 
originally  present  in  the  first  solution.  The  extraction  factor 
shows  at  a glance  the  completeness  of  the  extraction,  an  indicar- 
tion  of  the  value  of  the  extraction  under  those  conditions. 

The  partition  ratio,  the  term  used  in  the  past,  tells  only  the 
partition  of  one  molecular  species  between  two  layers  of  equal 
volume,  by  definition  of  the  term,  partition  ratio. 


II.  HISTORICAL. 


Dr.  C.  Kippenberger  (5)>  in  1897,  first  called  attention 
to  the  quantitative  solution  of  the  problem.  He  states  clearly 
the  possibility  of  error  due  to  the  hydrolysis  of  the  salt.  The 
use  of  Chloroform  or  a mixture  of  chloroform  and  a little  alco- 
hol is  suggested  for  a solvent. 

Three  years  later,  Kippenberger  (6),  published  a second  pa- 
per in  which  he  endeavored  to  establish  the  question  on  a firm- 
er basis.  He  worked  with  the  alkaloids,  strychnine,  brucine, 
atropine,  morphine,  aconitine,  veratrine,  papaverine,  narceine, 
codeine,  emetine,  pelletierine,  cocaine,  quinine,  narcotine, 
sparteine,  thebaine,  hyoscyamine,  daturine,  scopolamine,  and  the 
base  caffeine.  He  used  chloroform  and  ether  for  shaking  out. 

The  action  of  the  salts  of  the  following  acids  was  studied: 
hydrochloric  acid,  21.9$  HC1;  sulphuric  acid,  40.1$  H^SCL;  tar- 
taric acid,  and  oxalic  acid.  The  effect  of  the  addition  of  so- 
dium chloride  to  the  acid  solution  was  observed  in  some  cases. 

To  the  acid  solution,  he  added  the  immiscible  solvent.  Af- 
ter extraction,  he  separated  the  two  layers,  evaporated  off  the 
organic  solvent  and  determined  the  amount  of  alkaloid  and  alka- 
loidal  salt  extracted.  This  was  done  by  dissolving  the  residue 
in  N/50  standard  acid  and  titrating  the  excess  acid  with  N/50 
standard  alkali.  The  value  for  acid  neutralized  by  alkalbid  in- 
dicated the  amount  of  free  alkaloid  present  in  the  residue. 


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The  solution  was  then  made  alkaline  with  an  excess  of  sodium 
hydroxide  and  again  extracted  with  chloroform.  The  amount  of  to- 
tal alkaloid  was  obtained  by  evaporation  of  the  solvent  and  treat- 
ment with  standard  acid  and  alkali  as  before.  Subtraction  of  tte 
first  value,  or  free  alkaloid  present,  from  the  second  value, 
or  total  alkaloid,  gave  the  amount  of  alkaloid  present  as  salt. 

In  1901,  Hans  Proelss  (7)  gave  a short  description  of  the 
behavior  of  alkaloidal  solution  toward  different  solvents.  He 
endeavored  to  determine  first,  the  best  solvent  for  alkaloids 
as  a class,  and  second,  the  best  solvent  for  individual  alka- 
loids. He  compared  the  relative  extractive  powers  of  ether, 
chloroform,  benzene,  and  also  mixtures  of  ether  and  chloroform, 
and  alcohol  and  chloroform  for  the  alkaloids,  picro toxin,  ber- 
atrine,  strychnine,  atropine,  codeine,  and  morphine.  He  states 
that  constant  results  could  not  be  obtained  of  sufficient  accur- 
acy to  be  anything  more  than  comparative.  His  conclusion  is 
that  the  best  shaking  out  liquid  for  alkaloids  in  general  is 
chloroform  because  of  the  solubility  of  most  alkaloids  in  that 
solvent. 

Ed.  Springer  (8),  in  1901,  studied  the  effect  of  the  sol- 
vent chloroform  on  the  extraction  of  the  following  alkaloids: 
morphine,  coniine,  narcotine,  strychnine, quinine,  codeine, 
vereratrine,  and  cocaine  from  solutions  made  acid  with  sul- 
phuric, phosphoric,  hydrochloric,  tartaric,  acetic,  oxalic,  and 
citric  acids. 

The  amount  of  alkaloid  in  the  residue,  after  evaporation 
of  the  chloroform,  was  determined  by  titration  in  the  same  way 
as  by  Kippenberger . His  work  is  of  no  value  from  a quantita- 
tive stand-point  as  he  was  unable  to  obtain  checked  results. 

In  1906,  Simmer  (9)  published  an  important  paper  divided 
in  three  parts: 

1 . The  behavior  of  the  salts  of  the  common  alkaloids  to- 

ward extraction  by  chloroform  and  other  important 
solvents . 

2.  The  appearance  of  decomposition  through  treatment  with 

chloroform. 

3.  The  reducing  action  of  alkaloids. 

He  found  that  many  neutral  salts  are  extracted  by  both 
chloroform  and  benzene;  this  is  especially  true  of  the  salts  of 
nitric  and  the  halogen  acids. 

Many  authors  had  stated  that  the  extraction  of  alkaloids 
by  means  of  chloroform  is  attended  with  a decomposition  of  the 
chloroform  giving  rise  to  free  hydrochloric  acid.  Experimenting 
with  the  following  alkaloids:  atropine,  brucine,  quinine,  cincho- 
nidine,  cinchonine,  cocaine,  codeine,  morphine,  narcotine,  nico- 
tine, strychnine,  veratrine,  Simmer  found  that  the  action  of  the 
alkaloid  on  the  chloroform  is  negligible  except  in  the  cases  of 


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brucine  and  veratrine. 

In  1914,  Harden  and  Elliott(IO)  published  a paper  on  the 
methods  of  extraction  with  immiscible  solvents  from  the  point 
of  view  of  distribution  ratios.  They  worked  with  the  alkaloids, 
aconitine,  atropine,  codeine,  morphine,  quinine,  and  strychninq, 
using  chloroform  and  ether  as  solvents.  Ammonium  hydroxide  was 
used  to  make  the  solutions  alkaline. 

Prom  the  distribution  coefficient  and  a certain  subsequent 
algebraic  calculation,  they  could  determine  the  number  of  ex- 
tractions necessary  to  remove  99.9  per  cent  of  the  alkaloid. 

The  distribution  ratio  (d)  is  indicated  by  the  expression 

Concentration  in  10  cc.  of  water _ C _ , » 

Concentration  in  lOce.  of  non-aqueous  solvent  C ~ c 

The  algebraic  expression  for  the  calculation  of  the  num- 
ber of  shakings  necessary  for  an  extraction  indicated  by 

btnrr  ( — — Y*  where 
X0  \ e-  da  ) 

a = volume  of  the  aqueous  solvent. 

e = volume  of  non-aqueous  solvent. 

d = distribution  ratio. 

X0=  original  amount  of  material  to  be  extracted  in  the 
aqueous  layer. 

Xjj=  amount  of  material  in  the  water  layer  after"n" 
extractions . 

Beal  and.  Lewis  (11)  established  equilibrium  conditions  for 
the  following  systems  in  the  case  of  the  alkaloids,  aconitine, 
atropine,  brucine,  cinchonidine,  cinchonine,  cocaine,  codeine, 
morphine,  quinine,  strychnine,  and.  veratrine :- 

(a)  The  alkaloidal  tartrates,  tartaric  acid.,  water,  and 

chloroform. 

(b)  The  alkaloidal  tartseates,  tartaric  ax  id,  water,  and 

ether . 

(c)  Certain  alkaloidal  sulphates,  sulphuric  sxid,  water, 

and  chloroform. 

(d)  Certain  alkaloidal  sulphates,  sulphuric  acid.,  water, 

and  ether. 

(e)  Certain  alkaloidal  hydrochlorides,  hydrochloric  acid, 

water  and  chloroform. 

They  have  determined  the  extraction  factors  for  all  of 
these  systems,  as  well  as  those  described  in  the  literature, 
and  have  calculated  the  most  favorable  conditions  for  extraction. 

They  state  that  the  neutral  tartrates  were  prepared  by  dis- 


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solving  the  alkaloids  in  an  aqueous  acid  solution,  containing 
equivalent  amounts  of  tartaric  acid  in  a large  excess  of  water 
at  the  boiling  temperature.  The  acid  salt  which  forms  first 
stays  in  solution  and  the  remainder  of  the  alkaloid  completely 
neutralizes  it.  On  cooling  the  solution  slowly,  the  neutral 
salt  comes  out  in  beautiful  crystals.  In  one  or  two  cases,  it 
was  necessary  to  evaporate  some  of  the  solvent  water  in  order 
to  get  the  right  concentration  for  crystalization . 

They  also  state  that  the  mon-acid  may  be  prepared  by  dis- 
solving the  alkaloid  in  a slight  excess  of  acid  in  a small 
quantity  of  hot  water.  On  cooling,  the  crystals  of  the  acid 
salt  will  come  out. 

Allen  ( 12)  states  that  nicotine  forms  two  classes  of  salts, 
the  mon-acid  and  di-acid  salts.  He  further  states  that  most  of 
salts  of  nicotine  crystalize  with  difficulty,  the  acid  tartrate, 
to  which  he  gives  the  formula  C##H/fNa  ( C^HfcO^  ),  -f-  2 H^O  , being 

an  exception,  it  forming  in  handsome  tufts  when  ether  is  added 
to  it*s  alcoholic  solution. 

Hudson  (13)  has  investigated  the  solution  of  nicotine  in 
water  and  found  that  five  per-cent  of  nicotine  is  soluble  at  any 
temperature,  and  fifteen  per-cent  of  water  in  nicotine. 

Until  1911,  the  method  for  the  determination  of  nicotine, 
as  adopted  by  the  Association  of  Official  Agriculture  Chemists 
was  the  Kissling  Method  (14).  This  method  involves  two  series 
of  operations,  (1)  extraction  with  ether,  (2)  distillation 
with  steam  and  titration.  This  method  in  experienced  hands  and 
in  the  absence  of  certain  interfering  substances,  unquestionably 
yields  good  results.  The  final  determination  is  a volumetric  one 
and  the  end  point  is  rather  indefinite  especially  in  the  titra- 
tion of  distillates  from  eo  imereial  nicotine  preparations. 

In  1909,  Bertrand  and  Javillier  (Ip)  published  a paper  on 
the  use  of  silico-tungstic  acid  as  an  aid  m the  quantitative 

determination  of  nicotine.  In  their  method,  the  nicotine  was 
precipitated  with  silico-tungstic  acid,  the  nicotine  liberated 
from  the  nicotine  silico- tungstate  by  the  addition®*ealcined  . 
magnesia,  the  mixture  distilled  with  steam  and  the  nicotine 
determined  in  the  distillate  by  titration  with  standard  acid. 

In  conclusion,  Bertrand  afcd.  Javillier  suggested  that  the 
nicotine  might  again  be  precipitated  from  the  distillate  with 
silico-tungstic  acid  and  determined  gravimetrically  by  ignition 
to  Si-C^  and  WC^  . They  quote  no  experimental  work  on  this  theoret- 
ical consideration. 

Chapin  (16)  reports  the  development  of  this  method  as  car- 
ried out  by  the  United  States  Bureau  of  Animal  Industry.  It 
gives  results  which  agree  favorably  with  those  obtained  by  the 


6. 


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Kisslin  lethod.  They  give  0.114  as  the  factor  for  obtaining 
the  amount  of  nicotine  from  the  residue  of  silico-tungstic  oxide 


III.  EXPERIMENTAL. 


1.  Preparation  of  the  tartrates  of  nicotine. 


The  attempt  was  made  to  prepare  the  tartrates  of  nicotine 
as  suggested  by  Beal  and  Lewis.  For  the  neutral  salt  the  alkaloid 
was  dissolved  in  an  aqueous  acid  solution  containing  an  equiva- 
lent amount  of  tartartic  acid  in  a large  excess  of  water  at  the 
boiling  temperature.  For  the  acid  salt,  the  alkaloid  was  dis- 
solved in  a slight  excess  of  acid  in  a small  quantity  of  hot 
water.  Neither  salt  would  crystallize  out  either  upon  cooling, 
concentrating  and  cooling,  or  placing  in  a freezing  mixture. 


Salting  out  with  Rochelle  salts  was  then  tried.  A salt  crys- 
tallized but  upon  analysis  and  microscopiG.nl  examination  was 
proved  to  be  only  impure  potassium  bitartrate. 

The  next  procedure  was  to  dissolve  the  tartaric  acid  in 
alcohol  and  add  the  nicotine.  The  solution  was  then  concentrated 
on  a steam  bath.  The  salt  would  not  crystallize  until  ether  was 
added  to  the  alcoholic  solution.  No  matter  what  proportions  of 
nicotine  and  tartaric  acid  were  used,  the  analysis  of  the  salt 
showed  it  to  be  the  impure  acid  tartrate.  The  salt  did  not  form 
in  handsome  tufts  as  stated  by  Allen  but  formed  in  a pink  gum- 
my mass  which  crystallized  upon  standing  in  the  refrigerator. 

This  salt,  as  prepared  using  .an  excess  of  tartatic  acid,  con- 
tained 32.68  per  cent  nicotine.  The  theoretical  per  cent  of  nic- 
otine, if  CjoHI4N-  (CuH^O.  )x  + 2 HjjO  is  the  formula,  is  32.54  per 
cent,  if  Olt' ' CH  Hfc i s the  formula,  is  35 . 07pereent . Svi- 

dentally  the  crystals  contain  two  molecules  of  crystallization. 

2.  Preparation  of  nicotine  hydrochloride. 

Nicotine  was  disseized  in  anhydrous  ether  and  dry  hydrochlo- 
ric acid  gas  passed  into  the  solution.  The  hydrochloride  separa- 
ted in  a gummy  mass  which  became  crystalline  upon  drying  in  a 
vacuum  dessicator.  This  salt  upon  analysis  showed  30.62  per  cent 
hydrochloric  acid,  showing  that  the  acid  hydrochloride  was  the 
one  which  formed.  Theoretic.ally , the  anhydrous  salt  should  be 
31.04  percent  hydrochloric  acid  and  the  salt  with  one  molecule 
of  v/ater  of  crystallization  should  be  28.83  per  cent  hydrochloric 
ac  i d . 


7. 


3.  Preparation  of  pure  Nicotine. 

As  the  supply  of  pure  nicotine  was  limited,  it  v/as  neces- 
sary to  prepare  some  from  Black  Leaf  Forty,  an  insecticide  con- 
sisting of  a forty  per  cent  solution  of  nicotine  sulphate. 

A perforator  was  designed,  for  this  purpose.  The  solution 
of  Black  Leaf  Forty,  made  decidedly  alkal  ne  with  a concentrated 
solution  of  sodium  hydroxide,  was  placed  in  flask  A,  Fig.  1. 

In  flask  B,  which  was  placed  upon  a steam  bath,  was  an  almost 
saturated  solution  of  tartaric  acid.,  Ethei  poured  into  flask 

A through  the  condenser  until  it  flov/ed  out  of  the  arm  '.  As  the 
ether  passed  upward  through  the  tartaric  acid,  the  latter  ex- 
tracted the  nicotine  leaving  the  fats  and  other  substances  in 
the  ether.  As  flask  B was  heated,  the  ether  distilled  through 
arm  D and  ran  back  into  flask  A where  it  extracted  more  nico- 
tine and  again  ran  into  flask  B. 

When  the  solution  of  tartaric  3,cid  became  saturated  with 
nicotine, it  was  renewed.  The  acid  solution  was  then  made  alkaline 
with  sodium  hydroxide  and  shaken  several  times  in  a separatory 
funnel  with  ether  to  remove  the  nicotine.  The  ether  was  evapora- 
ted off  in  a vacuum  dessicator  and  the  nicotine  distilled  under 
vacuum. 

Two  samples  of  nicotine,  thus  prepared,  analysed  98.81  per 
cent  and  97.23  per  cent  pure  nicotine. 


4.  Determination  of  the  equilibrium  conditions  for  the 

partition  of  nicotine  between  aqueous  neutral  and  acid 
solutions  and  an  immiscible  solvent (ether ) . 

(a)  Extraction  of  the  neutral  or  acid  aqueous  solution  with 
ether. 

A weighed  amount  of  nicotine  v/as  washed  into  a two  hundred 
and  fifty  cubic  centimeter  volumetric  flask,  a calculated  amount 
of  normal  acid  was  added  and  the  solution  made  up  to  the  mark 
with  distilled  water.  Twenty-five  cubic  centimeter  portions 
were  m e a s ured  into  flasks,  twenty-five  cubic  centimeters  of  ether 
added,  the  flasks  stoppered  and  placed  in  a water  thermostat 
and  shaken  for  about  two  and  one  half  hours.  The  thermostat, 
which  was  accurate  to  within  a tenth  of  a degree,  v/as  maintained 
at  a temperature  of  twenty-five  degrees. 

After  the  time  of  shaking  had  elapsed  the  flasks  were  re- 
moved, and  ten  cubic  centimeters  of  the  ether  layer  pipetted 
into  a beaker  containing  a small  amount  of  water  and  about  five 
cubic  centimeters  of  dilute  hydrochloric  acid.  After  stirring, 
the  ether  was  evaporated  off  on  the  steam  bath.  The  solution 
was  then  diluted  to  about  seventy-five  cubic  centimeters  and  an 
excess  of  silico-tungstic  acid  v/as  added.  It  was  then  stirred 


. . 

. 


8. 


1 


until  the  precipitate  which  was  at  first  amorphous  became  crys- 
talline. The  beakers  were  then  removed  from  the  hot  plate,  al- 
lowed to  stand  over  night,  the  contentc^’iltered  on  quantita- 
tive filter  paper,  and  the  precipitate* with  cold  water  contain- 
ing one  cubic  centimeter  of  concentrated  hydrochloric  acid  per 
liter.  The  filters  were  then  ignited  in  an  electric  muffle  at 
bout  850°  to  constant  weight.  The  amount  of  nicotine  extract- 
ed was  determined  by  use  of  a factor  0.114  and  the  extraction 
factor  calculated. 


TABLE  I. 


Solution  containing  one  mole  of  tartaric  acid  to  four  moles 

of  nicotine. 


Wt.  of  nicotine 
in  10  cc. solution 

Length  of 

extraction. 

Wt.of  nicotine 

extracted. 

“ T 

Extraction 

factor. 

0. 042476  gm. 

2- 

hr. 

45niin. 

0,016006  gm. 

0.3768 

0.042476 

2hr . 

45min. 

0.016006 

0.3768 

0.042476 

2 

hr. 

45ciin. 

0.016006 

0.3768 

0.042476 

2 

hr. 

4 pmin . 

0.016051 

0.3779 

0.042476 

2 

hr. 

50min . 

0.016300 

0.3838 

0.042476 

2 

hr. 

50m in . 

0. Cl  6200 

0.3814 

0.042476 

2 

hr. 

50min. 

0.016210 

0.3816 

0.070300 

2 

hr. 

30min . 

0.026220 

0.3735 

0.070300 

2 

hr. 

30min. 

0.026500 

0.3770 

0.070300 

2 

hr. 

30min. 

0.025450 

0.3762 

0.070300 

2 

hr. 

30min . 

0.0264-0 

0.3762 

Average 

0.3780 

TABLE  II. 

Solution  containing 
moles 

; one  mole  0 
of  nicotine 

f hydrochloric  acid  to  two 

• 

7t.  of  nicotine  Length  of 

in  10  cc.  solution.  extraction. 

Wt.  of  nicotine 

extracted . 

Extraction 

factor. 

0.05692  gm. 

0.05692 

0.05692 

2 hr. 
2 hr. 
2,  hr. 

50  min. 
50  .min. 
50  min. 

0.02231 

0.02247 

0.02256 

Average 

0.3917 

0.3949 

0.3963 

0.3943 

/ 


) 


9. 


There  was  no  extraction  from  solutions  containing  as  much 
or  more  than  one  half  mole  of  tartaric  acid  to  one  mole  of  nico- 
tine. The  extraction  factors  obtained  for  a solution  containing 
one  mole  of  tartaric  acid  to  four  moles  of  nicotine  are  fouftd  in 

TABLE  I. 

There  was  no  extraction  from  a solution  containing  one  mole 
of  hydrochloric  acid  to  one  mole  of  nicotine.  The  factors  obtain- 
ed for  a solution  containing  one  mole  of  hydrochloric  acid  to 
two  moles  of  nicotine  are  found  in  TABLE  II.  They  are  slightly 
higher  than  those  obtained  from  the  tartaric  acid  solution  of 
equivalent  strength  which  are  found  in  ’EableJ.. 

(b)  Conditions  at  equilibrium  in  systems  in  which  the  alka- 
loid is  being  removed  from  its  ether  solution  by  an  acid  • 

The  quantity  of  nicotine  was  weighed  into  the  shaking 
flasks;,  twenty-five  cubic  centimeters  of  ether  added  and  the 
flasks  shaken  to  dis&dlve  the  nicotine  in  the  ether.  Twenty-five 
cubic  centimeters  of  normal  acid  were  then  added  and  the  flasks 
shaken  in  the  thermostat. 

Runs  were  made  to  see  if  there  was  more  extraction  by  the 
acid  at  the  end  of  an  hour  than  at  the  end.  of  a half  hour  but 
no  appreciable  difference  was  observed.  The  results  of  the  ex- 
tractions with  hydrochloric  acid  are  given  in  TABLE  III  and 
those  with  tartaric  acid  in  TABLE  IV. 


TABLE  III. 

Solution  of  nicotine  in  ether  shaken  with  N/ 1 HC1. 


Wt.  of  nicotine 

Wt.of  nicotine 

Extraction 

in  25  cc.  ether. 

extracted . 

factor. 

0 

0.  1494  gm. 

0 . 133465gni. 

0.8933 

0. 1327 

0. 1 18202 

0.8952 

0. 1442 

0. 129076 

0.8951 

0. 1440 

0. 123889 

0.8849 

0. 1518 

0.136372 

0.8983 

Average 

0.8934 

i 


. 


. 


■ 

. 

, 


' 


10. 


TABLE  IV. 

Solution  of  nicotine  in  ether  shaken  with  N/1  HTar. 


Wt.of  nicotine 
in  25  cc. ether. 

1 - - - - 

Wt.of  nicotine 
extracted . 

Extraction 

factor. 

0. 1080  grn. 

0.09670  gm. 

0.8954 

0. 1 167 

0. 10275 

0.8799 

0.0824 

0.07097 

0.8650 

0. 1 177 

0. 10887 

0.9252^ 

0.2014 

0. 18440 

0.9155 

from  Black  Leaf  Forty 

0.  1173 

0.10912 

0.9315 

r average  0.9229. 

0.1302 

0. 1 1950 

0.9191 

0.1277 

0. 1 1780 

0.9233J 

Average 

0.9068 

By  use  of  the  extraction  factor,  it  is  possible  to  deter- 
mine how  many  extractions  are  necessary  for  complete  removal 
of  an  alkaloid.  For  instance,  if  there  were  one  gram  of  nico- 
tine in  the  ether  solution,  the  first  extraction  with  N/1  Hy- 
drochloric acid  would  remove  89.34  per  cent  of  one  gram  or 
0.8934  grams  leaving  0.1066  grams.  The  second  extraction  would 
remove  89.34  per  cent  of  the  remaining  0. 1066  grams  leaving 
0.0114  grams.  The  third  extraction  would  remove  89.34  per  cent 
of  the  remaining  0.0114  grams  and  leave  only  0.0012  grams  or 
0,12  per  cent.  From  this, it  is  evident  that  three  extractions 
would  give  practically  complete  removal  of  the  nicotine. 

(c)  Extraction,  with  ether,  of  nicotine  salt  solutions 
to  which  sodium  hydroxide  has  been  added  in  amount  equivalent 
to  the  acid  in  the  salt. 

The  nicotine  tartrate  was  weighed  into  the  flasks,  standard 
sodium  hydroxide  added  to  neutralize  the  acid**Jdi  stilled  water 
added  to  bring  the  volume  to  twenty-five  cubic  centimeters.  An 
equal  volume  of  ether  was  then  added  and  the  whole  shaken  in  the 
thermostat  for  two  hours.  In  the  case  of  the  hydrochloride, a 
calculated  amount  of  normal  hydrochloric  acid  was  s.dded  to  the 
nicotine  and  standard  sodium  hydroxide  added  to  neutralize . it. 
For  some  reason,  close  checks  were  not  obtained.  The  results 
are  given  in  TABLE  V and  TABLE  VI. 


1 1 . 

TABLE  V. 


Nicotine  tartrate  in  solution . NaOH  added  to  neutralize  HTar. 


Wt.of  salt  in 
25  cc.  solution. 

Corresponding  Wt.of  nicotine 
v/t.of  nicotine.  extracted. 

Extraction 

factor. 

0.2941  gin. 

0.0961  gm. 

0.06765  gin. 

0.7038 

0.3652 

0.1153 

0.08880 

0.7450 

0.4749 

0.1552 

0. 1 1697 

0.7535 

0.3297 

0. 1077 

0.08137 

0.7558 

0.2844 

0.0929 

0.07002 

0.7568 

0.4143 

0. 1354 

0. 1C4C0 

0.7648 

0.3544 

0. 1158 

0.09147 

0.7900 

0.3995 

0.1305 

0.10355 

0.7935 

0.4585 

0. 1498 

0. 1 1925 

0.7970 

0.3348 

0.1094 

0.08755 

0.7985 

: 0.3623 

0. 1 184 

0.09537 

0.8050 

Average 

0.7694 

Nicotine  plus 

TABLE  VI. 

N/1  HC1  to  make  C H N (HC1)  . NaOH  added 
to  neutralize  HC1. 

Wt.of  nicotine  in 

Wt.of  nicotine 

Extraction 

25  cc.of  solution. 

extracted . 

factor . 

0.08322  gm. 

0.060977  gm. 

0.7330 

0.08322 

0.061 161 

0.7349 

0.08322 

0.064182 

0.7712 

0.08322 

0.064210 

0.7716 

0.08322 

0. 066063 

0.7933 

0.08322 

0.066177 

0.7952 

Average 

0.7665 

I 


12. 


IV.  Summary. 

1 . Pure  nicotine  has  been  obtained  from  Black  Leaf  Forty 
by  use  of  a perforator,  subsequent  extractions,  and  vacuum 
distillation. 

2.  It  is  impossible  to  obtain  the  tartrate  of  nicotine 
from  a water  solution.  It  is  readily  obtained  from  its  alcohol- 
ic solution  upon  the  addition  of  ether. 

3.  It  seems  evident  that  the  acid  salts  of  nicotine  are 
the  only  ones  which  it  is  possible  to  obtain  in  crystalline 
form.  In  contrast  to  this  conclusion  is  the  striking Wal  the 
neutral  salts  are  sufficiently  stable  in  solution  to  prevent 
any  extraction  of  the  nicotine  by  ether.  In  fact,  acid  of 
half  the  concentration  necessa,ry  to  form  the  neutral  salt  is 
sufficient  to  prevent  extraction  of  the  nicotine  from  the  sol- 
ution . 

4.  Equilibrium  conditions  have  been  determined  For  the 
partition  of  nicotine  between  aqueous  and  acid  solutions 

( tartaric  and  hydrochloric  acids)  and  an  immiscible  solvent 
(ether) . 


5.  The  most  practical  method  for  the  determination  of 
alkaloids  involves  the  extraction  of  the  alkaloid  from  an 
aqueous  solution  by  means  of  an  immiscible  solvent,  such  as. 
chloroform  or  ether. 


. 

r •.  UkJ 

r 

' 

i 

. 

. 

• 

. 

. 


. 


1 3. 


BIBLIOGRAPHY. 

1.  Dragendorff:  Die  ger^ich^tlich-chemische  Ermittelung  von 

Giften,  4 Aufl.,  p,  151. 

2.  Stas-Otto  : Ausmittelung  der  Gifte.,  7 Aufl.,  pp.  144&  280. 

3.  Beal  and  Lewis:  J,  Amer.  Pharm.  Assoc.,  5,  812-837,  1916. 

4.  Beal  and  Lewis:  Loc . cit. 

5.  KippeShberger,  G.  : Grundlagen  ftir  den  Nachweis  bon  Gif tstof- 

fen  bei  gerichtlich-chemischen  Uutersuch- 
ungen,  p,  56. 

6.  Kippenberg*€rC . : Zts.  f.  Anal.  Ch.,  1900,  39,  290-314. 

7.  Proelss, Hans : Apoth.  Ztg.,  1900,  16,  289-493. 

8.  Springer, Ed . : Apoth.  Ztg.,  1901,  17,  225-226. 

9.  Simmer;  Arch.  d.  Phar.,  1906,  244,  672. 

10.  Harden  and  Elliott:  J,  Ind.  Eng.  Ch.,  6,  928. 

11.  Beal  and  Lewis:  Loc.  cit.  at  3. 

12.  Allen:  Comm.  Org.  Anal.  4th  Ed.  VI,  238.' 

1 3.  Hudson, C . S. : Zeit.  Physikal  Chem. , 1904,  47,113. 

14.  U.  S.D.A.  Bur.  of  Chem.,  Bull.  107,  rev.  1910. 

1 5.  Bertrand, G.  ,&  Javillier,M,  : Bull,  des  Sciences  Pharrnacol- 

ogiques, tome  166,  no.1  pp. 

7-  14,  Jan.  1909. 

16.  Chapin, Robert  M. : U.  S.  Dept,  of  Agr.,  Bur.  of  Animal  Ind., 

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